Dual function seat belt retractor

ABSTRACT

A rotary lock assembly comprising a base having a shaft journaled therefrom for rotation in opposite directions between a first position and a second position through a third intermediate position a predetermined number of degrees of rotation from the first position toward the second position. The assembly includes deactivatable inertia actuated lock structure operatively associated with the shaft and the base and responsive to acceleration of rotation of the shaft toward the second position to lock the shaft against further rotation in that direction. Further, the assembly includes structure responsive to disposition of the shaft in a position between the first position and the intermediate position for deactivating the locking structure.

United States Patent [72] Inventor Joel A. Burns 917 Bank of theSouthwest, Amarillo, Tex. 1 79109 [21 1 Appl. No. 790,979 [22] FiledJan. 14,1969 [45] Patented Mar. 9, 1971 [54] DUAL FUNCTION SEAT BELTRETRACTOR Claims, Drawing Figs.

[52] US. Cl 242/1074 [51] Int. Cl Bh /48 [50] Field of Search 242/107(SB), 107.4, 107.5, 107.6; 297/385, 386, 388; 280/ (SB) [56] ReferencesCited UNITED STATES PATENTS 3,347,488 10/1967 Quinting 242/ 107.43,369,769 2/1968 Burns 242/107.4 3,412,952 11/1968 Wohlert et a1.242/1074 3,416,747 12/1968 Stoffel 3,450,368 6/1969 G1ausereta1....

' Primary Examiner-Stanley N. Gilreath Assistant Examiner-Werner H.Schroeder Attorneys-Clarence A. OBrien and Harvey B. Jacobson ABSTRACT:A rotary lock assembly comprising a base having a shaft journaledtherefrom for rotation in opposite directions between a first positionand a second position through a third intermediate position apredetermined number of degrees of rotation from the first positiontoward the second position. The assembly includes deactivatable inertiaactuated lock structure operatively associated with the shaft and thebase and responsive to ac ce leration of 101511011 of the shaft above apredetermined value in one direction of rotation of the shaft toward thesecond position to lock the shaft against further rotation in thatdirection. Further, the assembly includes structure responsive todisposition of the shaft in a position between the first position andthe intermediate position for deactivating the locking structure.

PATENTEDHAR 9mm j 3,568,948 sum 1 or 3 Fig Joel A. Burns 7 INIIiN'I'UK.

A nanny:

PATENTED MAR 9197: 3568.948

sum 3 or 3 Joel A. Burns Y gig z; BMW

DUAL FUNCTION SEAT BELT RETRACTOR There has recently beendeveloped'several types of rotary inertia locking seat belt retractorssuch as those disclosed in my prior,U.S. Pat. Nos. 3,369,768 and3,369,769. The seat belt retracting and locking mechanism disclosed inmy first above mentioned prior patent is operative to allow freeunwinding of the associated seat belt from its fully retracted posi-.tion toward an intermediate position at which further protraction of theassociated seat belt is terminated, unless the reel or shaft upon whichthe base end of the seat belt section is mounted is rotating above apredetermined f speed and the retractor is further operative topreventprotraction of the seat, belt once the predetermined minimumspeed of rotation of the shaft occurs in any position of rotation of theshaft past the intermediate position. The retractor includes lock outmeans for rendering the locking structure inoperative in response to acertain predetermined portion of the associated seat belt seetion beingwound on the shaft of the-retractor.

On the other hand, my second above-mentioned prier patent discloses aseat belt retractor operative, upon high rota tional speed or rapidacceleration of rotational speed of the shaft'of winding member in adirection to unwind the seat belt section therefrom, to lock the windingmember against further rotation in the direction unwinding the seat belttherefrom. Also, after the winding member has been locked againstrotation, to unwind the seat belt by high speed rotation or rapidacceleration of rotation of the Winding member, the retracting andlocking mechanism of the retractor disclosed in my second mentionedabove prior patent includes means by which further unwinding of theassociated seat belt section may be accomplished after the windingmember has been slightly rotated in a direction to wind the associatedseat belt section thereon as long as the subsequent rotation of thewinding member does not involve rapid rotation or rapid acceleration ofrotation thereof.

,While these previously patented seat belt retractors are fullyoperative to function in the manner in which they were designed tofunction, the first requires that the seat belt winding member berotated above a predetermined minimum speed of rotation in order toallow the seat belt to be protracted beyond a predetermined partiallyprotracted position and the second mentioned seat belt retractor enablesfree protraction of the associated seat belt section as long as rotationof the winding member in a direction to protract the seat belt sectionis not above a predetermined speedor i'apidly accelerated.

The immediately above referred to operating characteristics thereforerequire that a seat belt section to be used be at least initiallyprotracted in a prescribed manner. Inasmuch as some motorists and otherpersons using seat belts may be unfamiliar with the above-mentionedmodes 'of operation of these previous seat belt retractors, if suchpersons fail to at least initially protract the seat bel t sections ofthese previous retractors and they are, unable to successfully protractthe seat belt sections in order to attach them about themselves, theymaybe dubi- 1 ous of their capacity to function properly after beingproperly protracted or assume that they are in need of repairand not usethe seat belts. h

Accordingly, it is the main object of this invention to provide a rotaryinertia locking seat belt retractor which will be fully operative tolockthe associated winding member against further protraction after theseat belt section has been properly secured in desired protractedposition and yet which will allow the seat belt section to be initiallyprotracted in substant i ally any manner.

Another very important object ofsthis invention, in accordance with theimmediately preceding object, is to provide a rotary inertia lockingseat belt retractor which may be readily converted from a rotary inertiaresponsive locking action to a substantially positive locking action,merely be the removal ofa small spring. i

A further object of this invention, in accordance with the immediatelypreceding object, is to provide a seat belt retractor which issubstantially positive in its locking action after the associated seatbelt has been initially protracted and which will be completely free ofany form of springs which might incur. fatigue and malfunetiori.

' Another object of invention is to provide a seat belt retractor inaccordance with the preceding objects and including structural featureswhich will enable silent retraction of the associated seat beltretractor from a fully protracted position even though a ratchet-typeone-way lock mechanism is employed.

A final object of inyention to be specifically enu merated herein, is toprovide a seat belt retractor with automatic locking means andconstructed inaecordance with the preceding objeets which will conformto conventional forms of manufacture, beof simple construction and easyto use so as to provide a device that will be economically feasible,long lasting and relatively trouble free in operation.

These together withotherobjec ts and advantages which will becomesubsequently apparent residein the details of construction and operationas more fully hereinafter described and claimed, reference being had tothe v accompanying drawings forming a pa'rt'here'of, wherein likenumerals refer to like parts throughout, and inwhich:

F IG. Us a fragmehtary perspeetive view of a passenger seat constructionof a conventional form of motor vehicle shown with the associated seatbelt assembly utilizing the rotary inertia locking seat belt retractorof the instantinvention;

F1012 is a fragmentary perspective view of the seat belt retractor withthe rotary inertia locking components thereof in exploded position; h

FIG. 3 is an end elevational view of the retractor with the coverremoved from the rotary inertia locking mechanism end thereof; b

FIG.4 is a side elevational view of the assemblage illustrated in FIG. 3as seen from the right side thereof;

FIG. 5 is a fragmentaryenlarged vertical sectional view tekensubstantially upon the plane indicated by the section line 5-5 of FIG.3; h h

FIG. 6 is a fragmentary sectional view similar to FIG, 5 but with thelock but means in position to retain the locking member in itsinoperative position; h

FIG. 7 is a fragmentary elevational view similar to FIG. 5 butillustrating the locking member of the retractor in its locked position.I

FIG. 8 is a view similar to FIG. 5 and illustrating the locking memberrotated approximately from the position thereof illustrated in FIG; 7and disposed in the retracted position;

FIG. 9 is a view similar to FIG. 8 but with the spring removed andillustrating themanner in which the eccentric weighting of the lockmember will cause the lock member to shift to the operative positionwhen the heavier side of the lock member is disposed lowermost and theaxis of rotation of the winding member of the retractor is: horizontallydisposed; and

, FIG. 10 is a bottom plan view of the locking member of the retractor.h h

Referring now more specifically to thedrawings, the numeral 10 generallydesignates a conventional form of passenger vehicle having a seatconstruction generally referred to by the referenee numeral IZdisposedtherein and alongside of which a seat belt assembly generated referredto by the reference nnmerall f is disposed. The seat belt assembly 14includes'a retrzietor assembly referred to in general by thereferencenum'eral 16 having a seat belt'section 108 mounted thereon.

As can best be seen from a comparison of FIGS. 1, 2 and 4 of thedrawings, the retractor assembly 16 includes a frame referred to ingeneral by the reference numeral 18 and provided with a bifurcatedportion defining a pair of generally parallel end flanges or walls 20and 22 terminating at one pair of corresponding ends in web sections 24and 26, respectively, projecting toward each other and terminatinginwardly in parallel juxtaposed upstanding flange portions 28 and 30,respectively, which in turn terminate in juxtaposed mounting flangeportions 32 and 34, respectively, angulated relative to the flangeportions 28 and 30. The flanges or flange portions 32 and 34 includeregistered apertures 36 through which a bolt 40 may be fastened in orderto secure the frame 18 within the vehicle 10.

The retractor assembly 16 includes a shaft or winding member 38 which isjoumaled between the end flanges or walls 20 and 22. The end of theshaft 38 supported from the secured to the outer surface of the end wall22. The torsion spring 40 is operative to rotate the shaft 38 in acounterclockwise direction as viewed in FIGS. 3 and 7-9.

The end wall 20 is provided with a bore 44 therethrough in which thecorresponding end of the shaft 38 is joumaled. This end of the shaft 38includes a noncircular extension 46, see FIG. 2, on its terminal end andthe extension 46 includes a threaded blind bore 48.

A framelike plate 50 is secured to the outer surface of the end wall 20by means of suitable fasteners 52, 54 and 55 and the plate 50 definesratchet teeth 56 concentrically disposed about the center axis of thebore 44 and which face in a counterclockwise direction. In addition, agenerally cylindrical cam member 58 having a noncircular opening 60formed therethrough complementary to the shape of the extension 46 isdisposed on the extension 46. The generally cylindrical cam member 58includes a radially outwardly projecting portion or key 62 and thecylindrical outer peripheral surfaces of the cam member 58, exclusive ofthe key 62, are disposed about a center eccentrically disposed relativeto the center axis of the shaft 38.

A generally annular lock member referred to in general by the referencenumeral 64 is provided and has a cylindrical opening 66 formedtherethrough including a radial outward enlargement or recess 68 inwhich the key 62 of the cam member 58 is receivable. The circumferentialextent of the enlargement 68 is greater than the circumferential extentof the key 62 about the cam member 58 and accordingly, relativeoscillation between the key and the lock member 64 is afforded, to alimited degree.

The lock member 64 is provided with a pair of circumferentially spacedteeth 70 disposed adjacent each other in one area of its periphery andthe lock member 64 includes a small weight 72 on the area of the lockmember 64 upon which the teeth 70 are formed. In addition, almost adiametrically opposite portion of the lock mem'ber64 is provided with alarger weight 74 and the weight 74 includes a tongue portion 76 whichprojects into the opening or bore 68 formed through the lock member 64and terminates inwardly in an arcuate end edge portion 78.

A threaded mounting shank 80 having an abutment 82 thereon intermediateits opposite ends has one end threadedly engaged in the blind bore 48with the cam member 58 disposed on the extension 46 between the endflange or wall 20 and the abutment 82. In addition, the locking member64 is disposed over the cam member 58 between the abutment 82 and theend flange or wall 20. Also, a generally V-shaped anchor member 84 isembracingly disposed about the mounting shank 80 inwardly of theabutment 82 and outwardly of the cam member 58 and locking member 64.

A lockout disc 86 is provided and includes a central threaded bore 88.The lockout disc 86 is threaded on the outer end of the mounting shank80 and includes a cylindrical peripheral edge portion 90 for a purposeto be hereinafter more fully set forth. In addition, a butterfly spring92 is provided and has one of its angulated end portions 94 seated in abore 96 provided therefor in the key 62 and the other angulated endportion 98 thereof seated in a bore 100 provided therefor in the lockingmember 64, the butterfly spring 92 serving to yieldingly urge thelocking member 64 to the limit position thereof illustrated in FIG. 8-relative to the cam member 58 and to yieldingly resist rotation of thelocking member to the other limit position of oscillation thereofrelative to the cam member 58 illustrated in FIG. 7 of the drawings.

The lockout disc 86 includes a generally radially outwardly projectingarm 102 provided with a hooked end portion 104 on its outer end which isengageable with a wire anchor pin 106 secured to the plate 50 by meansof the fastener 52, see FIG. 2.

In operation, and assuming that the seat belt section 108 anchored tothe shaft 36 is in its fully retracted position, the butterfly spring 92urges the locking member 64 to its retracted position illustrated inFIG. 8 of the drawings with the teeth 70 out of engagement with theteeth 56. Thus, the seat belt member 108 may be protracted. Once theseat belt section 108 is substantially protracted, rapid acceleration ofthe shaft 38 in a clockwise direction to further protract the seat beltsection 108 also causes the cam member 58 to be rapidly accelerated, asit is carried by the shaft 38. The locking member 64 has a tendency(which tendency is increased by the weights 72 and 74) to cause thelocking member 64 to lag behind the cam member 58 during rapidacceleration of the latter and thus the cam member 58 rotates ahead ofthe locking member 64 in a clockwise direction and cams that side of thelocking member 64 upon which the teeth 70 are disposed outwardly towardengagement with the teeth 56, thus locking the shaft 38 against furtherrotation in a direction to protract the seat belt section 108. Thus,should a person secured by the seat belt structure 18 tend to continueforward movement during rapid deceleration of the vehicle 10 such asmight occur during an accident, the locking member 64 will quickly, withsubstantially no angular displacement of the locking member 64, functionterminate rotation of the shaft 38 in a clockwise direction as viewed inFIG. 8 of the drawings. Of course, the previously described operation ofthe seat belt structure 18 would also prevent rapid acceleration of theshaft 38 during initial protraction of the seat belt section 18.However, as previously hereinbefore set forth, this operatingcharacteristic of a rotary inertia locking seat belt retractor isundesirable. It is for this reason that the lockout disc 86 and tongue76 are provided.

The hooked end 104 of the arm 102 is engaged with the pin or rod 106 andthus prevents rotation of the lockout disc 86 during rotation of themounting shank as the shaft 38 is rotated. Accordingly, during rotation.of the shaft 38 the lockout disc 86, by its threaded engagement with themounting shank 80, moves along the latter.

Initially, when the seat belt section 108 is fully retracted, thelockout disc 86 is positioned as illustrated in FIG. 6 of the drawingswhich its diametrically reduced cylindrical peripheral edge portion inradial alignment with the arcuate free edge 78 of the tongue 76 thuspreventing displacement of the tongue 76 inwardly toward the mountingshank 80 and displacement of the teeth 70 outwardly from the mountingshank 80 toward engagement with the teeth 56. Thus, when the seat beltsection 108 is fully retracted, the cylindrical edge or surface 90 willprevent the locking member 64 from being cammed into engagement with theteeth 56 and the shaft 38 may be rapidly accelerated during initialprotraction of the seat belt section 188 without the locking member 64shifting to the operative position. However, when the shaft 38 has beenrotated a sufficient number of turns during initial protraction of theseat belt section 108, the lookout disc 86 moves outwardly along theouter end of the mounting shank 80 out of radial alignment with thetongue 76 and edge 90. At this point, rapid acceleration of the shaft 38in a direction protracting the seat belt section 108 will cause thelocking member 64 to be cammed into engagement with the teeth 56 so asto terminate rotation of the shaft 38. Of course, the hooked end 104 maybe disengaged from the pin 106 by bending the am 102 and the lockoutdisc 86 may be rotated relative to the mounting shank 80 before againengaging the hooked end 104 with the pin 106 so as to vary the number ofturns of the shaft 38 during initial protraction of the seat beltsection 102*] necessary to shift the edge or surface 90 out of radialalignment with the edge of surface 78.

in addition to the spring 92 tending to maintain the locking member 64in its inoperative position, the larger weight 74 on the locking member64 tends to maintain the locking member 64 out of engagement with theteeth 56 in response to high rotation of the shaft 38. Of course, thelarger weight 74 also tends to increase the inertia of the lockingmember 64 whereby a rapid increase in speed of rotation of the shaft 38in a direction protracting the seat belt section 108 will more quicklycam the locking member-64 into engagement with the teeth 56. The smallweight 72 is provided to somewhat offset the large weight 74 and it willbe noted that the weights 72 and 74 are not diametrically opposite eachother. In this manner, the weight represented by the small weight 72does not offset i an equal portion of the weight of the large weight 74.

function to prevent the locking member 64 from looking the shaft 38against rotation in a direction protracting the seat belt section 108until a predetermined protraction of the seat belt section 108 has beenaccomplished. Thereafter, the eccentric weighting of the locking member64 tends to maintain the locking member 64 in the inoperative positionuntil the seat belt section 108 has been extended the amount desired.Thereafter, after the seat belt section 108 has been buckled to theother corresponding seat belt section (not shown) and the spring 40 hasbeen allowed to rotate the shaft 38 in the reverse direction so as totake up the slack in the seat belt section 108;, subsequent protractionof the seat belt section 108. is substantially prevented, independent ofrapid acceleration of the shaft 33 in a direction to unwind the seatbelt section 108, inasmuch as there is inherent drag between the outersurface of the end flange or wall 20 and the opposing surface of thelocking member 64 tending to have the locking member 64 lag behindduring rotation of the shaft 38 in a direction to protract the seat beltsection 13. This inherent friction is more predominant if the axis ofrotation of the shaft 38 is disposed upright with the locking member 64disposed above the end flange or wall 20. in addition, should theretractor assembly 16 be inverted, inherent friction between the anchormember 84 and the outer face of the locking member 64 will tend to causethe latter to lag behind the shaft 38 when the latter is rotated in adirection to protract the seat belt section 108. Further, when the shaft36 is horizontally disposed and the various components of the retractorassembly are positioned as illustrated in H6. 9 of the drawings whichthe large weight 74 in approximately the 7 oclock position, any rotationof the shaft 38 in a clockwise direction to protract the seat beltsection 108 will tend to cause the side of the locking member 64 havingthe teeth 70 thereon to be cammed outwardly into engagement with theteeth 56 inasmuch as the friction between the cylindrical peripheralsurfaces of the cam member 58 and the opposing surfaces of the bore oropening 66 are not sufficient to elevate the large weight 74 toward the12 oclock position.

In review, it may be seen that the retractor assembly 16 is operativeeither with or without the butterfly spring 92 and that even if theoperation of the retractor assembly 16 with the butterfly spring 92 isdesired and the spring 92 should break or otherwise be renderedinoperative the retractor assembly 16 would be fully operative toprevent rotation of the shaft 38 in a direction to protract the seatbelt section 108 after the predetermined minimum amount of seat beltsection 108 has been protracted.

The lockout disc 86 prevents locking of the lock member 64 and the shaft38 during initial protraction of the seat belt section 108 and theeccentric weighting of the lock member 64 prevents locking of the lockmember 64 and the shaft 38 during rapid protraction of the section 108after the lock out disc has been shifted axially of the mounting shankto an inoperative position. Thereafter, once the protraction of thesection 108 has been terminated, the inertia locking feature of theretractor is fully operative, independent of any partial retraction ofthe section 108 to set or cock a locking mechanism. Also, the weights 72and 74 serve to increase the mass of the lock member 64 for more rapidinertia locking of the latter, to eccentrically weight the lock member64 for resisting its locking during rapid rotation of the shaft 38, andto enable the lock member 64 to lock in a positive member, independentof inertia, when the spring 92 is not used. 7

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modifications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention-to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay [be restored to, falling within the scope of the invention.

Iclaim:

1. A rotary lock assembly comprising a base including first stationaryabutment means, shaft means journaled from said base for rotation in onedirection from a first position toward a second position, through anintermediate position a'predetermined number of degrees from said firstposition and then rotatable in the opposite direction back toward saidfirst position, a movable locking component defining second abutmentmeans mounted on said shaft means for rotation therewith and supportedtherefrom for guided limited shifting transversely of the axis ofrotation of the shaft means relative to the latter and between first andsecond positions with a portion of the second abutment means positionedout of and in position, respectively, in direct engagement with thefirst abutment means to lock said shaft means against rotation relativeto said base, said shaft means and said movable component including camsurface means engageable with each other and operative, in response totorque above a predetermined value being applied to said componentthrough said shaft means in one direction of rotation of the componentthereof and substantially independent of rotation of the component withsaid shaft means relative to said base, to shift said component fromsaid first position toward said second position, and lockout meansresponsive to positioning of said shaft means in a position between saidfirst and intermediate positions for positively preventing movement ofsaid component to its second position of movement, said lockingcomponent including concave abutment surface means spacing radiallyinwardly toward the axis of rotation of said shaft means, said lockoutmeans including a lockout member supported from said base for limitedshifting axially of said shaft means and threaded on said shaft and heldagainst rotation relative to said base for travelling along said shaftmeans in response to rotation of the latter relative to said base, saidlockout means including a generally cylindrical surface concentric withthe axis of rotation of said shaft means and disposed in radial registrywith and immediately inwardly of said abutment surface means forabutment of the latter with said cylindrical surface when said shaft ispositioned between said first and intermediate positions, said lockmember, when said shaft means is positioned between said intermediateand second positions, being shifted along said shaft member to aposition with said cylindrical surface out of radial registry with saidabutment surface, said abutment surface, during shifting of said secondabutment means between said first and second positions thereof, beingshifted generally radially inwardly relative to said axis fora positionspaced a greater distance from said axis than said 4. The combination ofclaim 3 wherein said last-mentioned means comprises a spring.

5. The combination of claim 1 wherein said movable locking component iseccentrically weighted relative to the axis of rotation of said shaftand the eccentric weighting of said component tends to resist shiftingof said component to said second position, by centrifugal force, duringrotation of said shaft at high speed.

1. A rotary lock assembly comprising a base including first stationaryabutment means, shaft means journaled from said base for rotation in onedirection from a first position toward a second position, through anintermediate position a predetermineD number of degrees from said firstposition and then rotatable in the opposite direction back toward saidfirst position, a movable locking component defining second abutmentmeans mounted on said shaft means for rotation therewith and supportedtherefrom for guided limited shifting transversely of the axis ofrotation of the shaft means relative to the latter and between first andsecond positions with a portion of the second abutment means positionedout of and in position, respectively, in direct engagement with thefirst abutment means to lock said shaft means against rotation relativeto said base, said shaft means and said movable component including camsurface means engageable with each other and operative, in response totorque above a predetermined value being applied to said componentthrough said shaft means in one direction of rotation of the componentthereof and substantially independent of rotation of the component withsaid shaft means relative to said base, to shift said component fromsaid first position toward said second position, and lockout meansresponsive to positioning of said shaft means in a position between saidfirst and intermediate positions for positively preventing movement ofsaid component to its second position of movement, said lockingcomponent including concave abutment surface means spacing radiallyinwardly toward the axis of rotation of said shaft means, said lockoutmeans including a lockout member supported from said base for limitedshifting axially of said shaft means and threaded on said shaft and heldagainst rotation relative to said base for travelling along said shaftmeans in response to rotation of the latter relative to said base, saidlockout means including a generally cylindrical surface concentric withthe axis of rotation of said shaft means and disposed in radial registrywith and immediately inwardly of said abutment surface means forabutment of the latter with said cylindrical surface when said shaft ispositioned between said first and intermediate positions, said lockmember, when said shaft means is positioned between said intermediateand second positions, being shifted along said shaft member to aposition with said cylindrical surface out of radial registry with saidabutment surface, said abutment surface, during shifting of said secondabutment means between said first and second positions thereof, beingshifted generally radially inwardly relative to said axis for a positionspaced a greater distance from said axis than said cylindrical surfaceto a position spaced a lesser distance from said axis than saidcylindrical surface.
 2. The combination of claim 1 wherein said assemblyincludes means operatively connected between said shaft means and saidlocking component yieldingly urging said component toward said firstposition.
 3. The combination of claim 2 wherein the last-mentioned meansis readily removably connected between said shaft means and lockingcomponent.
 4. The combination of claim 3 wherein said last-mentionedmeans comprises a spring.
 5. The combination of claim 1 wherein saidmovable locking component is eccentrically weighted relative to the axisof rotation of said shaft and the eccentric weighting of said componenttends to resist shifting of said component to said second position, bycentrifugal force, during rotation of said shaft at high speed.